MS16 Calabration

[ron-e-g]

Update

I swapped track 2 & 3 cards. I performed an erase with tracks 1,2, and 3 armed. TRK 2 & 1 erased. Track 3 did not.

 

[fgonza2]

Is track 3 the only one not working ? what about 4-16 ?

Now swap card 3 with say card 10. or one that you know it works. what happens ? report back.

P.S make sure that when you swap cards the recorder is off and that the cards are inserted properly.

good luck.

 

[ron-e-g]

Actually Felipe, track 3 isn't the problem. It only became a problem when I switched Card 2 for 3. I just went through a record/play/erase for all tracks.
(Card 2 was back in it's proper location). All tracks performed fine, with the exception of track/card 2. It does not erase during record so what I'm starting to hear on it is a build-up of previous recording attempts. ? BTW, thanks for the heads-up. I do always switch off before removing any cards.

This has got me puzzled..I must have damaged something with that card insertion error! I just bet it was indeed track 2.

 

[fgonza2]

ok, so to confirm, if you put that card say on channel 10, then channel 10 won't work ?.

So the failure follows the channel where that card is installed. That means that there is a problem with that card, and we need to rootcause it. reconfirm that is the case. then we need to fnid out if the issue is only on record mode, or also in repro/sync mode. So check play the MRL tape with that channel on repro and sync mode. careful with the record mode, make sure you are not recording. Report back with results of that test.

 

[ron-e-g]

I swapped track 2 & 3 cards. I performed an erase with tracks 1,2, and 3 armed. TRK 2 & 1 erased. Track 3 did not.

This is after taking card 2 that would not erase track 2, and switching places with TRK 3 card. The card does NOT erase. The tape has what sounds like 3-4 layers of recorded passes on the tapes track 2 position, but that card (TRK2) will NOT erase. So if you want to know if that card plays both in repro and sync the answer is yes. But..maybe your asking if I hear the test tone in both repro/sync modes on the MRL? And if I do, how does it sound?

 

[fgonza2]

ok, so it looks like card 2 is the problem. how are you with soldering ? next steps is to trace the signal in the pcb card, component by component and try to locate the faulty component. You can also buy a full spare card - cost is ~$75 or so.

 

[ron-e-g]

Not so fast! I just realized, Yesterday when I was doing the record/play test, I still was hearing the multi record attempts, and even the 10K test signal on track 2. Remember I thought it all was erased when I switched cards, and put card 3 in 2's location? So... I'm going to have to investigate further.

 

[ron-e-g]

After doing some more checks. It is, as I earlier stated TRK 2's card will not erase. All others are fine. I loaded the MRL and All tracks play fine on both Repro and Sync.

What controls the erase/rec part of the card?

 

[fgonza2]

ok do the following test:

Take a reel of blank tape. and record something, does it record anything ?

Now, the schematics for the repro/play card is on page 9-10 in the manual. You may have fried U7, which is probably impossible to find at this point. But before concluding that. Check R211 that is not desoldered or separated in the board. Also check that it is not stuck at the max or min of its travel.

If all that fails, you need to put the scope to monitor the signal that goes to the erase head. Run the other experiments first.

 

[ron-e-g]

Did the test. Recorded signal on TRK/card 2. Played back sounds like its playing through a speaker with the rim torn completely loose! I then recorded signal to TRK1,card 1. Next I put Card 2 in 1's place and it played the previous recorded signal from card 1 fine.

So, it would seem the problem on card 2 is limited to the REC/ERASE section.

Also the R211 appears to pass the visual and pot test.

 

[fgonza2]

ok, check BIAS adjustment on the broken card. Have you considered on investing on a spare card ? you probably want to have one anyway. If not, i am not sure if you can repair it. Are you good at soldering and desoldering PCBs ?

 

[ron-e-g]

OK. Yes, I need some spares. I'm working on that right now. I will revisit BIAS adj. My soldering is getting better but not great. I do know someone who is capable though. Are you referring to the U7?

 

[fgonza2]

OK. Yes, I need some spares. I'm working on that right now. I will revisit BIAS adj. My soldering is getting better but not great. I do know someone who is capable though. Are you referring to the U7?

likely U7 is the culprit, but need to probe first. Now, U7 i dont know what part number is and if it is obtainable. Here's what i would do:

1. Measure the voltage on the erase head - you will need to use the RMS voltmeter for this. Hook it up to a scope probe and do it. You need to be super careful here as it is high voltage. Touching it can give you a strong shock and if there are any shorts you can fry other parts easily. Take all the precautions. Set the RMS voltmeter to 100 (maximum scale) for this. For hooking up the probe to the RMS meter, you will need a BNC to UHF adaptor. You can also use the scope for this. Set the probe to "X10" mode on the switch and be careful with the scale so it is high enough.

2. You will need to use the extender card for this and find the spots in the back of the PCB to probe the right points. You will be looking at the Erase head (+) and (-) which are on the connector. Be super careful when plugging in the card so you dont blow something else.

So, do this and report back. Do this slowly and don't bypass any steps. The signal that you'll see in the scope should be a sine-wave, not sure on the frequency let me check the schematics tonight when i get home.

 

[ron-e-g]

I've ordered two cards for the MS-16. fgonza2, did you ever check that Home Depot paint color?

 

[fgonza2]

good. how much did you pay for those and where did you get them ? i'll look up the paint code.

 

[ron-e-g]

ebay, 100.00 ea. The only ones I knew of.

 

[ron-e-g]

Just a final note before I put this to bed. I installed the replacement card,and all is well.

 

[fgonza2]

excellent are you happy now with the recorder ? make sure to keep participating in the forum and posting recordings and pictures.

 

[ron-e-g]

Thanks fgonza2. I am happy now, that I can start putting this gear to use! Got the M-600 problem sorted out also. I'll be around. Also plan to post pic's, of the rack mod I made for the M-600.

 

[duduac]

Hey guys! I got myself a MS16 couple of weeks ago and I haven`t had time to play with it cause I`ve been too busy with university assignment, but in two weeks time I`ll be on my uni break so it means I`ll have lots of free time and I wanted to set my MS16 to start recording all my ideas. I had a quick look at the manual and it tells me all the gear I need to do a proper alignment and calibration. As a I`m only a poor student that has no money I was wondering if I really need all that gear? I`ve got a MRL already and that`s pretty much it. I just need to know where to start from, as I plan to have soon all the gear to check everything, but at the moment my options are limited by my budget. The machine looks in great shape and I don`t think it needs much work right now, however I really want to get all this gear to set it up my way from the beginning to the end to have it working the best possible way but not right now...

Great thread BTW!!

Cheers