CurtPalme.com Home Theater Forum

[papalek]

The 4000 at my sisters has been running great now for over a year until today. When they went to turn it on it shows error 20 at board 44. Anyone know what that code means?

[tse]

First check the battery on the CPU bd. If ok check:

http://www.curtpalme.com/docs/Ampro_I2CError.pdf

Error XX at 44 means one of the TDA8444 DACs is in trouble. There are alot of them thoughout the projector. Each has it's own address like 4A, 42, 44......... The one with address 44 might be on the vertical bd like the table says or maybe not because the list is for X600 projectors.

Do you have service manual for 2000-4000 projectors?

Scott

[papalek]

The battery was new a year ago. I downloaded the manual but it will not open on this PC. I have boards from a 2000 that I can use to swap out. Just need a starting place.

[papalek]

Update. I went and looked it over and the fuse is blown for the +20v rail. I am going to replace the fuse and see what happens. But why did it show an IC error instead of low +20v? Second question,what would cause that fuse to blow? What does it supply?

[tse]

The +20V goes to just about everything. All the low level analog circuits use it. The TDA8444 that is at address 44 uses the +12V that is made from the +20V. Strange that you aren't getting alot of other errors.

I would unplug the HV supply, big connector, and replace fuse. If it blows again then start pullling boards until you find the one that blows the fuse. The fuse might not blow. Sometimes they will fail from fatigue.

scott

[papalek]

Update.
I tried to fire it up with the HVPS unpluged but it would not start. Open Interlock kept it from starting. I pluged it back in and pushed start. It froze up,with the +20 LED very dim and the +9 and -9 LEDs dim. It stayed like that for ablout 4-5 seconds and the fuse blew on the +20. Both the +9 and -9 Leds went to full brightness and it continued through the start up cycle. Fans run and it has error 20 at 44 and error 20 at 4e showing with the fuse blown. How will I be able to power it on with boards removed if the Open Interlock keeps it from starting?

[AnalogRocks]

There's a DIP switch for that if I remember correctly. Let me see if I can find my thread

[AnalogRocks]

There's a DIP switch for that if I remember correctly. Let me see if I can find my thread

[Tim in Phoenix]

Guys!

Where is Chip when an Ampro goes belly up?


.

[stefuel]

[tse]

Write on a sticker or piece of masking tape:

SW2 I2C bus error disable
SW3 Interlock Open disable

(this is for the long CPU card)

and stick on the chassis by the CPU card.

The tubes can't be hurt if the HV doesn't come up. Much safer to disable HV when chasing down this type of problem.

Scott

[macgyver655]

Error 20 means failure to acknowledge a write to a data address. And the address is 44. Here's what you must do. Completely ignore and disregard the errors. You are getting the errors because the 20v line is down. The address 44 cant acknowledge because there is no power to it.

I dont think the 4000 has a 20v down error in the software so it wont show that error. I think.

You must find the short on the 20v line. If you have a DMM and set it to diode or continuity and connect one end to the 20v fuse clip on the output and the other end to ground and see if it shows a short. If it does then try pulling boards until the short goes away.

The error wont go away by bypassing the interlock and pulling boards. But it may stop the fuse from blowing. You could put in another fuse and pull boards until the dim 20v led goes bright. But disconnect the HV first like Scott said.

[papalek]

I will try the DMM method first. 6.3A fuses are not easy to come by around here.

[papalek]

This was a pain in the ass. I started out with Mac's DMM method. I got an instant dead short reading on the fuse lead. I started pulling boards one at a time to try and find it. I still had a dead short every time. So next I pulled every board and wire off the mother board at once. I still had a dead short. I noticed a screw missing from a bracket and seeing how this is floor mounted,it might have went under the motherboard and was shorting it out. No luck,after pulling out the motherboard and inspecting it. I plugged the power supply back on to it and still had a dead short. What the hell is going on!!! I searched around and found that I did have another power supply to replace it with. I plugged in the new power supply to the motherboard and no short. Hurray!!!! I put everything back together and it fires right up. The short is somewhere in the SMPS. That is the first one that I have had fail on an Ampro.

[Curt Palme]

If you can't nail it, let me know..

[Curt Palme]

If you can't nail it, let me know..

[papalek]

The projector is working fine now. It is just a dead short in the SMPS that I took out.

[tse]

Good chance that it is the rectifier for the +20V rail. If it shorts you read through the diode, through the transformer winding (a piece of wire) to ground.

Scott

[macgyver655]

[papalek]

I was testing the output side.There was no fuse in the holder at the time.So it is definitely on the output side.

[tse]

Doh! Guess I wasn't listening well.

Scott

[macgyver655]