HP PL4245N - Fails to Power On

Hello. What you are describing is a failing component on the power supply. Some part is working momentarily and then heats up and fails. Replace the power supply and you will likely fix the plotter. Power supplies can be ordered from: 0950 2623R HP Designjet 700 750C 755CM Power Supply

What you are describing is the power supply failing because of bad capacitors.

HP xw6200 Workstation - Diagnostic LED Code: Four Flashes ISSUE: When the workstation is powered on, the front LED might flash red four times, once per second, followed by a two second pause. SOLUTION: The front LED flashing four times is a sign of a power failure. To fix this issue, complete the following steps:

1. Open the access panel, and check to see if the four-wire power supply cable is properly connected to the system board.
2. There may be a faulty device. Locate it by removing all devices and then reinstalling them one at a time until the workstation fails. Replace the device causing the failure. Continue adding devices to ensure all are functioning properly.
3. Verify the power supply functionality, as follows:
   1. Disconnect AC power.
   2. Remove all internal power supply cables from the system board.
   3. Plug in AC power.
      • If the power supply fan spins, and the BIST LED illuminates, then the power supply is good. Replace the system board.
      • If the power supply fan does not spin, or the BIST LED does not illuminate, replace the power supply.

Yes.

The Power Supply has a weak voltage power rail.

1) If ALL of the LED lights were on at once they would use less than 1 Watt of power.
(Amperes, {Amp's} times Voltage = Watts)

2) EACH fan uses 2 to 3 Watts of power.

3) A typical Processor may use 51 to 125 Watts of power. Just depends on what Processor it is.


A) Yellow light is a Diagnostic light. Blinking yellow tells you the Power Supply is bad.

B) When you unplug the 24-pin ATX main power cable from the motherboard, you have relieved the Power Supply of a load, temporarily.

The power supply then builds up enough power, that when you plug the 24-pin ATX main power cable back in, the fans run long enough until the built up power is drained.

How?
Inside the Power Supply are Electrolytic Capacitors.
They are used as Filters.
They filter the incoming AC electricity, and the outgoing DC electricity.

(They are in the Input Stage, and the Output Stage,

1) http://en.wikipedia.org/wiki/File:PSU-Open1.jpg

2) http://en.wikipedia.org/wiki/Switched-mode_power_supply

Click on the photo at the top right, to enlarge.

The first link above shows a side view.
The second link shows a top view.

The round objects that have a B on them are Electrolytic Capacitors.
They are in the Input Stage.

The ones to the right that surround the letter E, are also Electrolytic Capacitors, and they are in the Output Stage.

Basic construction of an Electrolytic Capacitor used in your power supply, is an aluminum shell case, three strips with a lead off of each one, (Wire), a cap at the top, a cap at the bottom, and Electrolytic Paste.

A) Three Strips:
1) One strip is a metal foil strip with the Positive lead attached to it.
It is the Conducting Strip.

2) One strip is a metal foil strip, and has a Non-Conducting medium applied to it.
It has the Negative lead attached to it.
It is the Non-Conducting Strip.

3) The last strip is a paper composite, and is soaked with Electrolytic Paste.

The case is a cylindrical aluminum shell.
At the top there is a flat, round aluminum disk. It has a K or X shape etched partway into it.

At the bottom is a round, flat synthetic rubber disk. It is the Bung.

The paper-like strip is laid in-between the two metal strips, and all three are rolled up tightly.
The two leads from the Conducting strip, ( + ), and the Non-Conducting strip ( - ) are inserted through the rubber bung at the bottom of the capacitor.

As an Electrolytic Capacitor fails it builds up gas inside. (Hydrogen Gas)
{Gas is created from the Electrolytic Paste }

The gas expands, and begins to push Electrolytic Paste out.
So much paste loss, and the capacitor operates, but at a weakened state.
Too much paste loss, and the capacitor fails.

This is why the computer may have turned on one time, and not the next. Then it fails to turn on at all because of a bad power supply.

This is NOT an invite to open your Power Supply, and attempt to repair it.
Those large capacitors shown in B, (Input Stage) may still be good.
Usual voltage ceiling for them is around 100 VOLTS!

If your fingers touch the two terminals on the bottom of a capacitor, (Radial Aluminum Electrolytic Capacitor), the stored power can be released to YOU!

If your fingers, or any of the rest of your hand, complete a circuit that any of the capacitors are in, the stored power can be released to YOU!

Shock can be from BAD to FATAL.

See if there is an unused computer with a good, compatible power supply, that you can borrow for a test unit.
Also make sure your computer is clean inside.
Dust, dirt, hair, food crumbs, spider webs, etc., will 'Kill' a Power Supply, and a computer F-A-S-T!

{It's just an ATX power supply. The type used in a LOT of desktop personal computers.
If you need a recommendation for a PSU, just hit me up in a Comment}

For additional questions please post in a Comment.

Regards,
joecoolvette

Not sure if this will help, but most caps fail with the in rush of power, over and over. Sounds like they were not made right. You might try a UPS ( uninterrupted Power Supply) this may help you with dirty power from your power company. And with high spikes. Make sure you get one that will handle the TV current draw. As far as upping the CAPs keep the same or slightly high voltage and increase in uf. You might find one that has the same uf and a higher voltage rating that will handle it.

May be a failing power or display board inside. In the last 5 or 6 yrs the stuff coming from China has been using a low grade knockoff version of the electrolytic capacitors and when the unit gets (on average) to about 2 to 4 yrs old the capacitors fail as the preservative that is supposed to be in the "dielectric" compound in them is not there and the capacitor fails. If you look at a circuit board and see those little cans on the board with shrink wrap on them with one side marked with a white strip of negatives and a K dimpled into the top - those are the electrolytics. The K is a weak point put there as a safety valve so if the capacitor fails it blows out there instead of exploding like a firecracker. Well a good sign of failure is a swollen top or even what is known as "bird poop" leaking from the top. Problems can range from no power at all to freaky occasional problems like yours. Capacitors cost very little but involve teardown of the monitor, checking the values of the bad ones, locating suitable replacements, desoldering the bad and soldering on new. Once new ones are installed then it's testing time.

You may want to locate a shop that does board level work to open it and at least assess the problem.

Failure of motherboards is usually due to breaking capacitors. A few years ago a capacitor company stole the "recipe" for making capacitors from another company and tried to make their own, unfortunately they did not get the ingredients right and the capacitors started breaking after 2-3 years of use. They sold these capacitors at very cheap prices and a lot of computer companies and power supply makers bought them. This is easy to diagnose. Look for capacitors (caps) (they look like little tiny soda cans) on your motherboard (mobo). They should be perfectly flat on top and not bulged or swelling or leaking anything. The dead giveaway is the fact that you are not getting a monitor signal and if you listen to your computer as it starts up, a few of the devices may not start (hard drive, etc). Mobos are usually expensive to replace because the computer makers have them made especially for them and only order so many. They usually do not have a lot of extras laying around. There are a few companies that will repair broken capacitor issues. Hope this explains why they can fail. They can also fail if overheated (like when a case cooling fan fails), the cpu is overclocked and not cooled down (which raises temps), the power supply fails or by lightning and power surges. Also if you add a bunch of extra components without upgrading the power supply you can suffer underpowered situations.
If you can get another power supply unit then you can try that first. Usually when the condition you describe happens it is either the motherboard or Power Supply. If you replace it with another PSU then you have to have at least the same or greater output watts.

Hello to all from Tom Arnold, WA6OVP

Subject: Repair of computer monitors or flat panel TV’s.

History:
Recently my wife's 27-inch AKAI (LCT21AS) 27-inch flat panel HDTV with DVD player quit working. Years ago, when I had an analog computer monitor quit operating; Joe Fadden WA6DDF had mentioned to me, that often computer monitor problems were caused by the monitor's power supply. Joe also said these power supply problems were often caused by failed electrolytic capacitors. Joe said he was able to fix many computer monitors by just changing all of the power supply electrolytic capacitors. Rather the fix that failed monitor, I just a bought a new one.

Symptoms:
The inoperative HDTV had been bought at COSTCO and had already been returned once to a COSTCO repair center for repairs. Cost to ship and insure the HDTV was 67 dollars. We received back a new HDTV set. Turn around time was over a month, with many long distance telephone calls being required. The new HDTV worked for about three months after it was received. When the returned HDTV failed, it trapped a DVD disc that had been left in the HDTV DVD player. The new HDTV failure symptoms were the same as the original HDTV failure. The red led indication would not change to green when the remotes power on button was pushed. There was no picture and no sound. The remote is required to operate the TV set.

Economics:
My wife's HDTV with internal DVD player was very expensive. Worse yet, the trapped DVD disc was the movie Flash Gorden Space Soldiers 1936. A local TV shop wanted 85 dollars to look at the failed HDTV; repairs were 75 dollars labor an hour plus parts. I quickly figured out that if I could fix the problem it would save a lot of time and money.

Internet Search:
I checked the Internet to determine if other AKAI owners had similar problems with their HDTV sets. There were lots of AKAI 27 inch and 32 inch HDTV set owners listing problems. Without exception all of the complaints concerned the HDTV power supply PC board and failed electrolytic capacitors.

General Internet Consensus:
Most of the AKAI HDTV sets worked just great and that many had been sold worldwide. There were some AKAI HDTV sets that did have power supply problems. Most of the AKAI HDTV set owners were not very pleased with either AKAI or the COSTCO response to the inoperative HDTV power supply problem.

Trouble Shooting:
All electrical power was removed from the HDTV set. The HDTV was placed face down on a workbench with a piece of cardboard to protect the display screen. The HDTV back panel cover was removed. There were many screws of several different sizes. The power supply PC board was separate from the rest of the set's components and was easily identified. The power supply PC board contained several different individual different voltage power supplies. Three electrolytic capacitors located on the PC board had obviously failed. The tops of these three capacitors were puffed out. Often when electrolytic capacitors fail they get over heated and the top of the capacitor is puffed out displaying an over pressurized appearance. The power supplies on the PC board were of the switching type. Switching type power supplies are also used in computer monitors to save money and weight.

Power Supply PC Board Removal:
The power supply PC board was mounted to the HDTV back panel with several screws. These screws were removed. There also several multi-pin connectors attached to the PC board. These connectors were numbered with a black felt marker to ensure correct reinstallation. The connectors were Hot-glued in place. A sharp knife was used to remove the hot glue. The connectors were removed.

Repair:
The three suspect failed capacitors were easily removed. The three capacitors were each 1000 ufd and rated at 16 working volts. The other power supply PC board electrolytic capacitors were visibly checked. Three new capacitors were installed, they were rated at 1000 ufd at 25 working volts. On the PC board the three electrolytic capacitors were in just one of the power supply circuits and were identified as EC18, EC19, and EC20.

The New Electrolytic capacitors:
These were low impedance / high reliability radial lead polarized aluminum capacitors, they have a plus and minus connection pins. Correct installation of any polarized capacitor is required. The three new electrolytic capacitors were specifically designed and rated for service in switching type power supply circuits. Switching type power supply electrolytic capacitors need to be both very robust and designed for use in high frequency circuits. General-purpose aluminum electrolytic capacitors should not be used in switching type power supplies, if capacitors designed for switching power supplies can be obtained.

Final Repair Steps:
The PC board was reinstalled without the electrical connectors to the PC board being hot glued. The HDTV back panel cover was refastened. Watched episodes one through five of Space Soldiers. It was well worth the time and three electrolytic capacitors to fix the problem. The repairs saved a lot of time and money. The repair was very simple and not the least challenging. It took longer to remove and then reinstall the HDTV back cover panel than it took to replace the three failed capacitors.


Safety:
These types of repairs should not be attempted without a complete understanding of the dangers involved with working on electrical equipment, especially working around power supplies and charged capacitors. Proper desoldiering and soldiering techniques need to be used.

Conclusions:
Flat screen computer monitors and TV sets do fail. Repairs of electronic equipment can be very expensive. When your computer monitor or flat screen TV does fail, you might consider a visible inspection of the equipments power supply. A simple repair might save you a lot of time and money.

Hello to all from Tom Arnold, WA6OVP

Subject: Repair of computer monitors or flat panel TV’s.

History:
Recently my wife's 27-inch AKAI (LCT21AS) 27-inch flat panel HDTV with DVD player quit working. Years ago, when I had an analog computer monitor quit operating; Joe Fadden WA6DDF had mentioned to me, that often computer monitor problems were caused by the monitor's power supply. Joe also said these power supply problems were often caused by failed electrolytic capacitors. Joe said he was able to fix many computer monitors by just changing all of the power supply electrolytic capacitors. Rather the fix that failed monitor, I just a bought a new one.

Symptoms:
The inoperative HDTV had been bought at COSTCO and had already been returned once to a COSTCO repair center for repairs. Cost to ship and insure the HDTV was 67 dollars. We received back a new HDTV set. Turn around time was over a month, with many long distance telephone calls being required. The new HDTV worked for about three months after it was received. When the returned HDTV failed, it trapped a DVD disc that had been left in the HDTV DVD player. The new HDTV failure symptoms were the same as the original HDTV failure. The red led indication would not change to green when the remotes power on button was pushed. There was no picture and no sound. The remote is required to operate the TV set.

Economics:
My wife's HDTV with internal DVD player was very expensive. Worse yet, the trapped DVD disc was the movie Flash Gorden Space Soldiers 1936. A local TV shop wanted 85 dollars to look at the failed HDTV; repairs were 75 dollars labor an hour plus parts. I quickly figured out that if I could fix the problem it would save a lot of time and money.

Internet Search:
I checked the Internet to determine if other AKAI owners had similar problems with their HDTV sets. There were lots of AKAI 27 inch and 32 inch HDTV set owners listing problems. Without exception all of the complaints concerned the HDTV power supply PC board and failed electrolytic capacitors.

General Internet Consensus:
Most of the AKAI HDTV sets worked just great and that many had been sold worldwide. There were some AKAI HDTV sets that did have power supply problems. Most of the AKAI HDTV set owners were not very pleased with either AKAI or the COSTCO response to the inoperative HDTV power supply problem.

Trouble Shooting:
All electrical power was removed from the HDTV set. The HDTV was placed face down on a workbench with a piece of cardboard to protect the display screen. The HDTV back panel cover was removed. There were many screws of several different sizes. The power supply PC board was separate from the rest of the set's components and was easily identified. The power supply PC board contained several different individual different voltage power supplies. Three electrolytic capacitors located on the PC board had obviously failed. The tops of these three capacitors were puffed out. Often when electrolytic capacitors fail they get over heated and the top of the capacitor is puffed out displaying an over pressurized appearance. The power supplies on the PC board were of the switching type. Switching type power supplies are also used in computer monitors to save money and weight.

Power Supply PC Board Removal:
The power supply PC board was mounted to the HDTV back panel with several screws. These screws were removed. There also several multi-pin connectors attached to the PC board. These connectors were numbered with a black felt marker to ensure correct reinstallation. The connectors were Hot-glued in place. A sharp knife was used to remove the hot glue. The connectors were removed.

Repair:
The three suspect failed capacitors were easily removed. The three capacitors were each 1000 ufd and rated at 16 working volts. The other power supply PC board electrolytic capacitors were visibly checked. Three new capacitors were installed, they were rated at 1000 ufd at 25 working volts. On the PC board the three electrolytic capacitors were in just one of the power supply circuits and were identified as EC18, EC19, and EC20.

The New Electrolytic capacitors:
These were low impedance / high reliability radial lead polarized aluminum capacitors, they have a plus and minus connection pins. Correct installation of any polarized capacitor is required. The three new electrolytic capacitors were specifically designed and rated for service in switching type power supply circuits. Switching type power supply electrolytic capacitors need to be both very robust and designed for use in high frequency circuits. General-purpose aluminum electrolytic capacitors should not be used in switching type power supplies, if capacitors designed for switching power supplies can be obtained.

Final Repair Steps:
The PC board was reinstalled without the electrical connectors to the PC board being hot glued. The HDTV back panel cover was refastened. Watched episodes one through five of Space Soldiers. It was well worth the time and three electrolytic capacitors to fix the problem. The repairs saved a lot of time and money. The repair was very simple and not the least challenging. It took longer to remove and then reinstall the HDTV back cover panel than it took to replace the three failed capacitors.


Safety:
These types of repairs should not be attempted without a complete understanding of the dangers involved with working on electrical equipment, especially working around power supplies and charged capacitors. Proper desoldiering and soldiering techniques need to be used.

Conclusions:
Flat screen computer monitors and TV sets do fail. Repairs of electronic equipment can be very expensive. When your computer monitor or flat screen TV does fail, you might consider a visible inspection of the equipments power supply. A simple repair might save you a lot of time and money.

Hello to all from Tom Arnold, WA6OVP

Subject: Repair of computer monitors or flat panel TV’s.

History:
Recently my wife's 27-inch AKAI (LCT21AS) 27-inch flat panel HDTV with DVD player quit working. Years ago, when I had an analog computer monitor quit operating; Joe Fadden WA6DDF had mentioned to me, that often computer monitor problems were caused by the monitor's power supply. Joe also said these power supply problems were often caused by failed electrolytic capacitors. Joe said he was able to fix many computer monitors by just changing all of the power supply electrolytic capacitors. Rather the fix that failed monitor, I just a bought a new one.

Symptoms:
The inoperative HDTV had been bought at COSTCO and had already been returned once to a COSTCO repair center for repairs. Cost to ship and insure the HDTV was 67 dollars. We received back a new HDTV set. Turn around time was over a month, with many long distance telephone calls being required. The new HDTV worked for about three months after it was received. When the returned HDTV failed, it trapped a DVD disc that had been left in the HDTV DVD player. The new HDTV failure symptoms were the same as the original HDTV failure. The red led indication would not change to green when the remotes power on button was pushed. There was no picture and no sound. The remote is required to operate the TV set.

Economics:
My wife's HDTV with internal DVD player was very expensive. Worse yet, the trapped DVD disc was the movie Flash Gorden Space Soldiers 1936. A local TV shop wanted 85 dollars to look at the failed HDTV; repairs were 75 dollars labor an hour plus parts. I quickly figured out that if I could fix the problem it would save a lot of time and money.

Internet Search:
I checked the Internet to determine if other AKAI owners had similar problems with their HDTV sets. There were lots of AKAI 27 inch and 32 inch HDTV set owners listing problems. Without exception all of the complaints concerned the HDTV power supply PC board and failed electrolytic capacitors.

General Internet Consensus:
Most of the AKAI HDTV sets worked just great and that many had been sold worldwide. There were some AKAI HDTV sets that did have power supply problems. Most of the AKAI HDTV set owners were not very pleased with either AKAI or the COSTCO response to the inoperative HDTV power supply problem.

Trouble Shooting:
All electrical power was removed from the HDTV set. The HDTV was placed face down on a workbench with a piece of cardboard to protect the display screen. The HDTV back panel cover was removed. There were many screws of several different sizes. The power supply PC board was separate from the rest of the set's components and was easily identified. The power supply PC board contained several different individual different voltage power supplies. Three electrolytic capacitors located on the PC board had obviously failed. The tops of these three capacitors were puffed out. Often when electrolytic capacitors fail they get over heated and the top of the capacitor is puffed out displaying an over pressurized appearance. The power supplies on the PC board were of the switching type. Switching type power supplies are also used in computer monitors to save money and weight.

Power Supply PC Board Removal:
The power supply PC board was mounted to the HDTV back panel with several screws. These screws were removed. There also several multi-pin connectors attached to the PC board. These connectors were numbered with a black felt marker to ensure correct reinstallation. The connectors were Hot-glued in place. A sharp knife was used to remove the hot glue. The connectors were removed.

Repair:
The three suspect failed capacitors were easily removed. The three capacitors were each 1000 ufd and rated at 16 working volts. The other power supply PC board electrolytic capacitors were visibly checked. Three new capacitors were installed, they were rated at 1000 ufd at 25 working volts. On the PC board the three electrolytic capacitors were in just one of the power supply circuits and were identified as EC18, EC19, and EC20.

The New Electrolytic capacitors:
These were low impedance / high reliability radial lead polarized aluminum capacitors, they have a plus and minus connection pins. Correct installation of any polarized capacitor is required. The three new electrolytic capacitors were specifically designed and rated for service in switching type power supply circuits. Switching type power supply electrolytic capacitors need to be both very robust and designed for use in high frequency circuits. General-purpose aluminum electrolytic capacitors should not be used in switching type power supplies, if capacitors designed for switching power supplies can be obtained.

Final Repair Steps:
The PC board was reinstalled without the electrical connectors to the PC board being hot glued. The HDTV back panel cover was refastened. Watched episodes one through five of Space Soldiers. It was well worth the time and three electrolytic capacitors to fix the problem. The repairs saved a lot of time and money. The repair was very simple and not the least challenging. It took longer to remove and then reinstall the HDTV back cover panel than it took to replace the three failed capacitors.


Safety:
These types of repairs should not be attempted without a complete understanding of the dangers involved with working on electrical equipment, especially working around power supplies and charged capacitors. Proper desoldiering and soldiering techniques need to be used.

Conclusions:
Flat screen computer monitors and TV sets do fail. Repairs of electronic equipment can be very expensive. When your computer monitor or flat screen TV does fail, you might consider a visible inspection of the equipments power supply. A simple repair might save you a lot of time and money.