What is the recommended service for 2004 chevy

2005 Chevy Trailblazer service manual said the same 345-395 kPa (50-57 psi)

no- no recall on the fuel tank that cracks at the filler neck the following link are complaints about fuel tank that are recieved if you go to home page and enter trailblazer they give you the break down of the whole series of model and complaints as well as recall information they also list the TSB technical service bulletins
2004 Chevrolet Trailblazer Crack In Fuel Tank

Your owners manual will tell you exactly what service is needed at your 75,000 miles.

That really depends on the quality and quantity of maintenance done on the vehicle. With 140+K miles your looking at 20 - 23K miles per year. Does the owner have service records, were all the manufacturer's recommended maintenance done at the proper intervals. Has the transfer case fluid been changed every 50K miles? Front and rear differential fluids at 100K? Any transmission service work done? Plugs should have been changed at around 100K.

Your transmission/transfer case needs to be flushed and the fluid replaced along with any needed screens or filters that are recommended by GM.
Your owners manual should have info on the manufacturers reccomendations.

Most of the car dealers recommend to perform Maintenance services scheduled at 30K, 50K, 90K and so on.
At 30K they mostly inspect all the systems, and replace fuel filter.
At 60K they inspect systems and flush must of the fluids, transmission oil and filter, coolant, brake fluid, differential and transfer case fluid, and replace the air filter. Some replace the spark plus at 60K some at 100K.
At 90K all timing belts are replaced, and the status of the timing chain checked. A deviation of more than 5 degree means, there it is the time ayes on the timing chain.
At the Owners manual for 2005 Chevrolet Trailblazer recommend:
Inspect all the systems at 25K, and replace fuel filter.
Replace engine air cleaner filter, automatic transmission fluid, automatic transfer case fluid every 50K.
Replace spark plugs every 100K.
Maintenance Services for your car are scheduled at 25K, 50K, 75K,100K and so on. All are tune ups but they are not the same.
The only concern for GM is the GM Dex-Cool antifreeze. There are some complaints regarding this product. I recommend to flush the cooling system every 50K to 60K.

You will only need to remove the headlight assembly. This is done by pulling up on the two tabs at the back of the assmebly then lift up and out.

The VVT (variable Valve Timing) solenoid may be dirty and will need to be cleaned or replaced. Poor maintenance (lack of oil change) will cause carbon and sludge to accumulate on the VVT screen causing the VVT to stick which will cause the issues your experiencing.
You may get lucky by trying to clean the VVT by adding a can of Seafoam to your engine oil and running it in there for the next 250 miles and then giving the Trailblazer oil and filter service with the recommended 5W-30 weight oil, anything heavier may cause the VVT not to function correctly as it is now.
Start with the simple and add Seafoam (Auto Zone, Part Source) carries the product. Service the engine oil after 250 miles, and at worst you may have to replace the VVT solenoid which is simple to do. Keep me posted if you have to replace the VVT.
Thank you for using fixya and be safe

according to the repair guide at autozone.com, there is a filter listed and the guide states that if there is a fuel tank shield, it must be removed to access the filter. autozone.com has the procedure for replacing the filter as well as many other maintenance and troubleshooting procedures. register and enter you vehicle info to access.

I have a 06 Z71 and it did the same thing so more than likely your just going to have to buy a new cd player. I would recommend going with an aftermarket cd player because you probably going to spend just as much on another stock unit.