Been spending a little time the last several nights working on the 388.
There was a tweaked connector on the power supply PCB...was getting some intermittent power issues to the system logic...so I repaired that and reflowed all the solder joints to the connectors on the power supply PCB as well as on the corresponding joints on the motherboard. All better now.
It's pretty much all cleaned up...I'd give it a solid 8+/10. Degaussed the headblock assembly, aligned the meters, and aligned the playback label. Tomorrow I'll finish up with checking the bias levels and doing the record level alignment.
Because I've been noticing the tape packs are sloppy I wanted to double check the tape tensions, so I did that tonight too.
The tension arm roller positions in PLAY mode were pretty much spot-on, as were the holdback and takeup tensions. REW and FFWD tensions were another story...they were both 20-30g too high. I have a suspicion the thicker tape that came with the machine (456 vs 457 or LPR35) is to blame...betcha if I'd mounted some 1mil tape those tensions would be closer to spec. But it's setup for the 456, and I'm going to be selling some with the machine so I dialed in the REW and FFWD tensions.
There's another typo in the manual: on page 1-27 of the service manual, the reel servo PCB reference chart says trimmer R105 is associated with the FFWD mode tension setting, and R206 is the trimmer to adjust the tension in REW mode...that's backwards. R105 does the REW tension, and R206 does the FFWD tension.
Anyway, the tape packs are improved now.
And here it is at the close of tonight's work...I've gone through and double checked all the functions and it still kinda floors me...I'm not used to stuff just working, but absolutely everything works.