Recent content by david winter

AU-999 021080376 Details (as never moded until restoring and improving it): - 2SA640 on all preamp boards - CDC8002/9002 / XA495 on driver boards - Subsonic filter present (version with 2 signal wires) - Crowbar circuit present at speaker outputs

Hello, I need to replace the blue "ladder" slide which links the front panel rotary input switch to the linear input switch on the input board. The thin flat metal strip has broken and I can't manage to solder something on it. I don't know the right term for this part, and can't find a...

Thanks for your answers. I'll finally opt for the simplest solution: replace the mains cable with an earhed one (and remove the 2M resistor).

Hello, I'm going through a nice Denon PMA-701 amp. Seems a bit cheap in manufacture, but worth restoring. The tone control uses a number of 2SC1775 and 2SC1000. Haven't replaced any yet. The output stage also has a pair of 2SC1775 which I plan to replace by 2SC1845 unless there is a better...

The audio problem is fixed. The real problem is that I don't know if there's an earth problem where the MAC 1900 is being used. If there's an earth issue at the AC plug but not at the antenna amplifier (which isn't connected to the same AC line). You just send the AC leak to the antenna...

Hi, I'm working on a MAC 1900 for someone who apparently had troubles with a blown external antenna amplifier system. The MAC 1900 works in 230Vac mode. The person called an tech to replace his antenna stuff, and the tech measured a 108Vac leak from the FM antenna plugs and the earth, which is...

Hi, I'm trying to figure out why the radial motor of a Mission DAD-7000 (Philips CD-104) no longer moves. The CD loads and stops spining after 2 around seconds. Before this happened, the player was almost working despite one silent channel (the other just turned bad with white noise in play...

Thanks a million times for taking the time to picture your boad. That's really helpful :) The green wire is barely visible on the far right of my picture, just between the white and black wires. Looks almost black. Time to put everything back in place, and check the regulated psu.

Thanks, that would be great ! :thumbsup: If you look at my initial pictures, you will see a jumper on the solder side (red arrow). All I need to know is where it goes as it was put back incorrectly. Its end near the border is correct, but the other isn't.

Your board has the same mods than mine. All other photos found around the web didn't match. Do you still have the receiver ? There are holes on the chassis edges which, with proper lighting, allow seeing the underside of the board partially. Thanks for your photos!

The board has several differences: - R461 replaced by 1µF / 25V (in series with the 47K as explained above) - R468 replaced by 100µF / 25V (C493). This is visible on Rev. C schematic below. - TR415 is confusing because its reference should have been put closer to it instead of next to a NPN. I...

Thanks for posting this. It's version D, which differs from my board which has a few differences, including a 330K resistor between pins 4G and Gnd. This 330K is in series with the 47K (in place of D409) going to the base of TR416 (2SC711) and the - of a 0.1µF electrolytic, which + goes nowhere...

I forgot to mention that the right side of the strap (red arrow) is correctly soldered. It goes to the + of a 1µF electrolytic, itself in series with a 100K resistor. The problem is with the other side which was put to the wrong place as per picture: cathode of D491 / + 100µF/25V / emitter of...

Hi there, I'm working on a QR-6500 which has the same F-1322 board but with a few changes (like two resistors in place of two diodes). One additional 1uF cap as well as one additional 330K resistor don't show in the SM. There's a strap on the solder side with one end put at the wrong place, and...

Hello, I am close to finish restoring a QR-6500 (serial is 211091683 if this can help with differences / mods). I need to verify the position of a strap (see picture below) on the solder side of the F-1322 decoder board. The service manual seems to have the right schematic (at least something...