Hi all. I'm triying to bring back to life this old player. AZ6801, philips. 1989.
When I got it, it don't power up. I find fast why. The power regulator, which output 5v for the microcontroller, was bad, and in their out pin, it has 7,8v.
I change it for a 7805, and bingo, display began to works, and i saw the pattern that this player shows at boot, before do focus or anything more.
Other failure, was a TDA7072 burned, and now its changed also.
Ok, now, it powers up, but do nothing. ONLY moves the pickup to the initial position, and thats all.
Laser dont lit, Cd dont spins...
If I force láser on, cheating the APC circuit, it works and goes on. But, if i play with the levels of the door switch, and pickup initial position swicht, microcontroler dont mind, and no lits the láser nor try to focus.
When I test the original damaged regulator, i saw overvoltage in his output. It must be 5 v, but was giving 7,8, and, since it powers the microcontroller, i think that this overvoltage could fríed the controller.
But, hey, as i've said, the controller works well the display and positions the pickup in the initial position, from there, now it must power the láser, and do the focus search., but dont do anything more. So, is not died.
Thats all. What do You thing? Damaged brain? I'm losting something? I accept gratefully any help or thinking.
Marry Christian, and all the Best from Spain.
Albert.
When I got it, it don't power up. I find fast why. The power regulator, which output 5v for the microcontroller, was bad, and in their out pin, it has 7,8v.
I change it for a 7805, and bingo, display began to works, and i saw the pattern that this player shows at boot, before do focus or anything more.
Other failure, was a TDA7072 burned, and now its changed also.
Ok, now, it powers up, but do nothing. ONLY moves the pickup to the initial position, and thats all.
Laser dont lit, Cd dont spins...
If I force láser on, cheating the APC circuit, it works and goes on. But, if i play with the levels of the door switch, and pickup initial position swicht, microcontroler dont mind, and no lits the láser nor try to focus.
When I test the original damaged regulator, i saw overvoltage in his output. It must be 5 v, but was giving 7,8, and, since it powers the microcontroller, i think that this overvoltage could fríed the controller.
But, hey, as i've said, the controller works well the display and positions the pickup in the initial position, from there, now it must power the láser, and do the focus search., but dont do anything more. So, is not died.
Thats all. What do You thing? Damaged brain? I'm losting something? I accept gratefully any help or thinking.
Marry Christian, and all the Best from Spain.
Albert.
Assume you have the service manual. Do you have have a scope too? Might be necessary for much in the way of troubleshooting.
Looking at AX6801 service manual it shows the MCU as being TMP47C221AF. A brief datasheet for it is available at: https://pdf1.alldatasheet.com/datasheet-pdf/view/32473/TOSHIBA/TMP47C420AF.html Also looks like some similar Toshiba CMOS MCUs are rated for a maximum Vdd of 7v. Seems likely that 7-8v is something it could likely survive, although 8v may be really pushing it. Since some of its functions seem to be working, I would probably assume for the moment that its not the problem.
Looking at AX6801 service manual it shows the MCU as being TMP47C221AF. A brief datasheet for it is available at: https://pdf1.alldatasheet.com/datasheet-pdf/view/32473/TOSHIBA/TMP47C420AF.html Also looks like some similar Toshiba CMOS MCUs are rated for a maximum Vdd of 7v. Seems likely that 7-8v is something it could likely survive, although 8v may be really pushing it. Since some of its functions seem to be working, I would probably assume for the moment that its not the problem.
Hi Markw4. Yes, I have the service manual, and an oscilloscope.
I've test the data, lach and clock of the controller, with the scope and, guess? NOTHING.
Not a single swing. The three pins are 0 volt fixed.
So, I strong thinking the controller has at least, the PIO pins death.
I've found in eBay another 6800/6801, and when I get it ( its travelling from Italy), I change the PCB and we Will see.
Happy new year, for all.
Alberto
I've test the data, lach and clock of the controller, with the scope and, guess? NOTHING.
Not a single swing. The three pins are 0 volt fixed.
So, I strong thinking the controller has at least, the PIO pins death.
I've found in eBay another 6800/6801, and when I get it ( its travelling from Italy), I change the PCB and we Will see.
Happy new year, for all.
Alberto
the AX6801 schematic is for a jvc car amp, (ks-ax6801), im looking at one as we speak , or maybe i missread something.
Hi all. The other AZ6800 is now at home, but you Will have to wait some days. I'm now fighting with a Sony D-303, changing the pickup.
Stay tuned .
Stay tuned .