A90 just appears after switching on.

code p 0300 refers to random/multiple cylinder misfires detected ===causes spark plugs ---HT leads ---injector/s--ignition coil/s---low compression---wiring
code p 0522 refers to engine oil pressure sensor/switch--low voltage ===causes wiring short to ground ---engine oil pressure sensor /switch---ECM
for the first code having to alter the accelerator position ( which tells the ECM to let in more fuel indicates either a low pressure in the fuel manifold or that the injectors need cleaning
At high way speeds when the engine appears to be running good , it is still possible to have random misfires caused by low fuel pressures and /or dirty injector tips
It would be a good idea to check the oil pressure with a mechanical gauge ,then replace the oil pressure sensor/switch

Karbonn A90 hard reset 1. Charge the battery 100%. 2. Turn off your KArbonn Andorid phone. Turn ON the device by pressing and holding the VOLUME UP key and the power key together until the phone shortly vibrates. 3. When Android system recovery menu appears, release VOLUME key. 4. Highlight wipe data/Factory reset using volume key. 5. Confirm with Power or Cancel using BACK key. 6. After hard reset is done, highlight reboot system now and confirm your selection. Note! All data will be deleted!

look in the handbook as i have no idea sorry ,i suspect low brake fluid but iam no doubt wrong

1. Check your power cord & adapter.
2. If its working then check the battery, reseat the battery & check.
3. If available then check with another battery
4. If no, then remove the battery & switch on the PC in AC mode.
5. Check if battery charging indication or AC power on indication is glowing. if not then need to change ur motherboard.
6. If indication is OK, but could not power ON then check ur RAM for any loose connection or dust. clean & reinstall.
7. If still no display, connect an external monitor, check if display is comming.
8. If Display is coming then your LCD need to replace.

We have a Canon A520 and it was having all the symptoms noted. Searched for a resolution on numerous sites including the Canon Support site. While on the Canon Support site, I found an FAQ on "How to RESET the A520". Turn camera on, find and hold MENU button for 5+ seconds until "Reset settings to default?" screen appears. Arrow over to OK and press the SET button. When we did this the battery low indicator showed, replaced batteries with standard alkaline batteries. Everything functions properly, with no additional problems for the past 5 days. I guess the camera just lost its mind and had to be defaulted and rebooted, hope this helps.

Theres a firmware update, try this

http://www.4shared.com/dir/2953073/a0908d81/sharing.html

A- I have a Pentax Opio S hence I had to get the "fwdc110p.bin" file here:

http://www.badongo.com/file/707791

B- Drop this file on your SD Card at the root directory (same level as DCIM folder) or as described by the following link and then close your camera to OFF:

Attention: Do not load this file yet onto the camera i.e. the menu+power on procedure, follow step C first...

Important!!! Insert a fully charged battery or connect to an external power source.

C- Open the now infamous "Secret Menu" in order to re-initialize your camera prior to re-installing the new firm ware: Simultaneously press MENU + Flash symbol button + Power ON...a white screen with data written in black should show.

Then a sequence of buttons must be pressed: 2 times the focus button (flower, mountain, MF symbols button) followed by 2 toggles to the Right of the "OK" button...then press MENU once and voile...the Secret Menu appears!

Using the down toggle of the OK button, go to ROM UPDATE then go down to "SYSTEM INITIAL" and press OK. Press another OK to re-initialize your camera.

Once this has been completed, turn your camera off.

D- Load the firm ware by opening your camera with the MENU+Power ON procedure...finally this should be posting "Complete" after the "Loading" message, instead of the "Error!" that we initially kept on having.

Your camera should be working perfectly! Only thing is that you will have to redo your personal settings on it from scratch...but hey, this is much better than to wait for months to get your camera back from Pentax and save that money for your next photogenic trip!

Only Pentax Technical Help support team wil be able to tell you what A90 means There may be a FAQ for that camera on the site - have you looked?

Try JAYCAR www.jaycar.com.au take the fuse into the store. You should get something to do the job. Be aware that the fuse may have blown for a reason and may be an indication of something more serious.

A- I have a Pentax Opio S hence I had to get the "fwdc110p.bin" file here:

http://www.badongo.com/file/707791

B- Drop this file on your SD Card at the root directory (same level as DCIM folder) or as described by the following link and then close your camera to OFF:

Attention: Do not load this file yet onto the camera i.e. the menu+power on procedure, follow step C first...

Important!!! Insert a fully charged battery or connect to an external power source.

C- Open the now infamous "Secret Menu" in order to re-initialize your camera prior to re-installing the new firm ware: Simultaneously press MENU + Flash symbol button + Power ON...a white screen with data written in black should show.

Then a sequence of buttons must be pressed: 2 times the focus button (flower, mountain, MF symbols button) followed by 2 toggles to the Right of the "OK" button...then press MENU once and voile...the Secret Menu appears!

Using the down toggle of the OK button, go to ROM UPDATE then go down to "SYSTEM INITIAL" and press OK. Press another OK to re-initialize your camera.

Once this has been completed, turn your camera off.

D- Load the firm ware by opening your camera with the MENU+Power ON procedure...finally this should be posting "Complete" after the "Loading" message, instead of the "Error!" that we initially kept on having.

Your camera should be working perfectly! Only thing is that you will have to redo your personal settings on it from scratch...but hey, this is much better than to wait for months to get your camera back from Pentax and save that money for your next photogenic trip!