Issue with Crate TX50DB Limo battery amp

[retrorod]

Hey folks, Want to know if anyone has had experience with the battery operated Crate TX 50DB Limo? The owner says its making noises. It plays fine to me except when in SLAP or DELAY mode on the DSP dial. After 5 or 10 minutes of warm-up, there is a little bit of electronic static at the end of the of the note when driving it hard? Hard to explain, but it is not very musical. Other than that, it seems to play like a normal cheezy SS amp modeling amp. Anyone have any experience with these? Or any idea what would cause this? I believe it is not too old. 2001 or later?
Is 10 years 'obsolescence' on some of these 'modern marvels'? Could it be the battery 'going south'? How do you know?
Thanks for any enlightenment....Rod

[Jazz P Bass]

Crate Limo

The battery should read 12-13 Vdc when charged.
I had one of these come in a while back.
The battery had a bad cell (would not charge past 6 Vdc).
It also had weird noises going on.
I resoldered/reflowed the whole amp.
Even the DSP board.
That resolved the noises.
PS: Make a drawing of where the connectors go. It is not hard to mix them up.

[retrorod]

Thanks Jazz P bass. Makes sense to me! On the subject of re-soldering/re-flowing these pcb,s. I have discovered that there is often -times a film on them that seems to make the re-flowing process a little slower and messier than it would otherwise be when starting with clean surface pads. Can anyone enlightment me on what is the best way to clean the board prior to re-flowing? Is there a certain product/technique that works well for cleaning oxidation or flux residue from the back of pcb,s?

[pecorporation]

Had a couple of those where the problem was in the pc board jumper cable plugs. The pressed in wires were not pressed in all the way. May wanna glance at those as well.

[retrorod]

Thanks, I will check those also. Another thing I notice with this amp....With unit on(no inputs) when rotating the DSP pot, there is static(crackle) when rotating through the various effects AND when turned to the bypass mode there is a continuous high-pitched tone emitted. This doesn,t seem right. I don,t have a footswitch to check out that function. Any ideas on that?

[pecorporation]

Sounds like failing solder connections to me. Verify your power source is up to snuff, 12-13VDC and then go looking for solder faults.

I would just reflow everything (like Jazz P stated), jacks, pots, output amp, filter caps, large resistors and even the pc plug pins. Also, spray a little deoxit in those pots & jacks. Using solder flux helps break down solder surface oxidation and allows the solder to flow smoothly.

[abqsunrise]

My Crate amp has the same problem as retrorod explains in his post. I took the advice of pecorporation. I opened up the amp and removed all the PC boards and one by one put a soldering iron to each solder point on all of the PC Boards. Some places looked like it needed a bit more solder so I supplied that in places as I went along. After about an hour of working this I was done. I put everything back together I tested the amp out and it worked perfectly again. I was really happy that this fixed the problem. I was at the point that I thought I was going to have to unload this amp for parts. This amp has been performing well for nine years now and has made a lot of tip money for me. Not to mention that these amps are no longer available.

[Jazz P Bass]

Not the first amp that needed to be resoldered.

Good job.

[i2eye]

Soldering tips/advice

Hi, when the resoldering/reflowing work is performed, are there any tips or advice on the type of iron I should use? I've done soldering plenty of times before but I want to avoid overheating any of the components that are heat sensitive. I want to avoid sending my PC board to a tech and get charged a huge amount for just adding more solder. Thank you! - Ruben

The battery should read 12-13 Vdc when charged.
I had one of these come in a while back.
The battery had a bad cell (would not charge past 6 Vdc).
It also had weird noises going on.
I resoldered/reflowed the whole amp.
Even the DSP board.
That resolved the noises.
PS: Make a drawing of where the connectors go. It is not hard to mix them up.

[Enzo]

You rarely damage the parts with soldering heat, but what DOES get damaged is the board itself, you can lift the copper pads off the board. And that happens from using too COOL and iron or lingering too long. Get a good hot iron, 750 degrees is common some guys use 800, get the joint hot, flow solder into it, then back off. The trouble comes when some one heats the joint, thinks it maybe isn;t good enough, heats it again, adds more solder, then heats it some more to smooth the solder. That will destroy the glue that holds the copper to the board. Same thing with not enough heat or too weak an iron. It takes way too long to get the joint hot enough for solder to flow, but that heat on teh pad for extended period lifts the pad.

Learn to solder with confidence.

[i2eye]

Thank you! That's a huge help! Be well and I'll let you know what happens.

You rarely damage the parts with soldering heat, but what DOES get damaged is the board itself, you can lift the copper pads off the board. And that happens from using too COOL and iron or lingering too long. Get a good hot iron, 750 degrees is common some guys use 800, get the joint hot, flow solder into it, then back off. The trouble comes when some one heats the joint, thinks it maybe isn;t good enough, heats it again, adds more solder, then heats it some more to smooth the solder. That will destroy the glue that holds the copper to the board. Same thing with not enough heat or too weak an iron. It takes way too long to get the joint hot enough for solder to flow, but that heat on teh pad for extended period lifts the pad.

Learn to solder with confidence.

[J M Fahey]

As a side note: NO battery lasts 15 years.

[i2eye]

As a side note: NO battery lasts 15 years.

Thanks! I just ordered a new one a few days ago. I figure I'd start fresh.