david winter
Classical music lover.
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 mode).
I didn't restore the player so far but did the following:
- Refreshed almsot all solders, and checked both servo / decoder boards several times. Also refreshed the psu and tray boards.
- Checked voltages at the power supply board: ok at +/- 200mV
- Did a basic test of the OKI 2128 RAM chip which tests good with my TL-866 tester. I don't know whether it works correctly at the player's read/write speeds. I have a spare 6116-15 just in case (I socketed the 2128 with a gold-plated tulip socket).
- Replaced the BF494 (Hfe 58 as opposed to the 115+ in the specs)
I did no recaping so far even though I know this is (almost) always crucial (I restored a few CD104 so far).
Most voltages around the radial motor are ok as per SM. The only difference I noticed so far was at test point <25> which says +1.2V on Page 36 (link between LM339 and BC548 just under the TCA240). I have 0.58V there.
Any ideas ? Thanks !
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 mode).
I didn't restore the player so far but did the following:
- Refreshed almsot all solders, and checked both servo / decoder boards several times. Also refreshed the psu and tray boards.
- Checked voltages at the power supply board: ok at +/- 200mV
- Did a basic test of the OKI 2128 RAM chip which tests good with my TL-866 tester. I don't know whether it works correctly at the player's read/write speeds. I have a spare 6116-15 just in case (I socketed the 2128 with a gold-plated tulip socket).
- Replaced the BF494 (Hfe 58 as opposed to the 115+ in the specs)
I did no recaping so far even though I know this is (almost) always crucial (I restored a few CD104 so far).
Most voltages around the radial motor are ok as per SM. The only difference I noticed so far was at test point <25> which says +1.2V on Page 36 (link between LM339 and BC548 just under the TCA240). I have 0.58V there.
Any ideas ? Thanks !