Dead SX-1 - Can somebody please help?


Oct 4, 2012
Gear owned
2 SX-1 LE+ DVRA1000 CD-01U
as everyone probably knows, I have a dead SX that I'm trying to revive...someone on the forum PM'ed me and said they would help, but after many emails and many months, he's always too busy, on vacation or has other matters to attend to...he was going to walk me through how to test the power on the unit, so I bought a voltmeter...I don't know how to check the power without help...I was also told to take out the 4 glass fuses and inspect them...well, after I removed the fuses, I noticed that one is a different voltage, but have no idea which one it is!!! I ASSumed they were all the same...the person who volunteered to help said that Redbus had a spare power supply I could have if I paid shipping, but only after we checked out the power first...
I'm lost...I have a dead SX sitting on my garage floor for several months collecting dust and don't have a clue how to fix it or even if it CAN be fixed...I'm not even sure what RAM card it takes because the ones I bought (same specs), didn't work in either SX...and that may or may not be an issue...
maybe I should just use the dead SX for spare parts, but it was great having the 2 synced together and having 32 tracks simultaneously...I want to have them both working in harmony again...
I know the SX forum is dying off, but is there anyone left who can offer some help?
right now, nothing, since I removed the fuses and put the unit in my garage...before that, the Time Code Display would have something on it (not numbers) and nothing else was on except the green disk faders moved at all and the screen was blank...pretty much dead and not responding to the start-up disk...
OK.Does the CPU fan work?Have you reseated the CPU,the RAM,and all the cards that plug into the Motherboard?Do you have a service manual?Have you verified the CMOS battery on the motherboard reads appox.3 volts? In all the years I worked on the SX-1,(worked at Tascam), I never saw a power supply fail-but it's always possible.Russ at NJ Factory Service,(Tascam authorized servicer), is pretty good with the SX-1.Let me know the answers,I'll help if I can.
yes...I did all that and put fresh batteries in both SX's...Russ was the one who said he was going to help me with this and told me about the CPU that Redbus had available if I needed it...I do have the service manual, but still can't figure out what's wrong...I'm far from being an expert at fixing or even troubleshooting electronic equipment...that's why Russ was going to help me figure out if it's a power issue...I believe that the cards are fried, because I inadvertently touched my pliers against one of the cards and sparks flew and the screen went dead at that moment...before that it was freezing at "Fader Calibration Ended"...
The LCD backlight could have been taken out by the pliers.The big connector on the Motherboard with the black,(ground),red,(+5 volts), and yellow,(+12 volts),wires can be measured with your meter. Does the hard drive spin up?Get it all back together and do the voltage measurements.Let me know what you find.
I have a voltage meter, but I don't know how to do the voltage measurements...Russ was going to walk me through it...
If you look down at the M/B by the CPU, you will see a multi-wire connector.It has the black,red and yellow wires.Connect the black,(-),lead of your meter to the black wire.Touch the red lead,( +), to the red wire.It should read +5 volts.Touch the red lead of your meter to the yellow wire .It should read +12 volts.I didn't see answers to the questions I have asked.That would be the first step in resolving your problem.
I won't have the SX back together until some time this weekend...the CPU fan does work...I'll check the HD and voltage s soon as I put it all together...I still don't know which of the 4 fuses is different...3 of them say 250 V-4A and 1 says 250V- I'm not sure which fuse goes where without taking my other SX apart (which I can't do now, since I'm in the middle of a project)... anyway, once the fuses are in correctly, I can check the voltage & HD...
thanks for helping
I looked through the Service manual and can't seem to locate the information about the fuses...what page is it on?
I looked through the Service Manual again and still can't locate any info about the fuses...I'm probably overlooking it or not understanding what I'm looking at...either way, can someone tell what page it's on or even better, if you know the correct way to replace the fuses...

or I can wait until I finish the project I'm working on (a couple of months) and look at the fuses in the working SX...why is there one fuse that's different? I really wish I had checked each one before popping them all out...oh well..
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I just searched the old forum and couldn't find the answer...does anyone have their SX open to take a look or maybe knows without opening her up?
If you compare the last page in the schematic section,( page 79),of the service manual with page 17 in the parts list,(gather pcb assy power),-F1 and 2 are 4 amp fuses,F3 is a 1.6 amp fuse and F4 is a 4 amp fuse.
OK...I see it on page 71...I guess I didn't know what I was looking at!!!
for $150 (+ $25 S/H) and LCD screens for $135 (+$14 S/H)...I'm not sure I need a power supply, but I do need 2 new screens...but I don't have enough money and can only afford the shipping costs...and now the CD Drive isn't "being detected" at start, if I ever have to boot from the CD, I won't be able's probably an issue with the ribbon cable...the dead SX had a similar problem a few years ago...does anyone have some spare parts laying around??? :(
I switched the ribbon cable and that wasn't the problem...I had to swap out the CD drive from the dead SX and that works fine...I guess I'll be using the dead SX for parts, since I don't think there's any hope to revive it...sad, but I have no choice...
I just had one of my machines open to install a drive bay and removable drive caddy so i took a photo of the fuses on the power supple board. This should identify the fuses and the current rating of each fuse. It is all printed on the top side of the power supple PC Board.


  • PS Fuses.jpg
    PS Fuses.jpg
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