-
Hi Guys,
I'm looking for a schematic for one of these bad boys:
actually, I only really need to know what component (and value) this is:
I think it's a capacitor.. (the side of it has 'popped' off - looks like heat has done it) but as you can see from the pic it appears to be the only component in that bunch without an identifying letter/number...
If I knew what to replace it with, I've got adequate soldering skills for the task.
Thanks guys.
-
07-24-2022 05:12 AM
-
If it’s the part indicated by the letters rs5 it’s a resistor. Probably high power
Sent from my iPhone using Tapatalk
-
You’re talking about the component between R51 and D1, correct? I can’t see the reference designator, but the symbol on the board under the component looks like the same symbol used on the caps, such as C36. So, it’s probably a capacitor. Can you get a better picture of the component? You may have to remove it from the board to get a good look at it. Sometimes you luck out and the value is printed on it…
You might be able to find a sch on the net via google. Here’s one that came up, could be a slightly different version:
Circuit Diagram(Main Board Analog) - Roland CUBE-60D Service Manual [Page 22] | ManualsLib
-
Originally Posted by blue-moves
-
Originally Posted by 73Fender
another thing is to power up the amp
and play it till the heat gets up to the
point that the amp fails
(maybe use a looper pedal to keep playing)
the use a cold spray to cool down that actual component and see if that component is causing the failure/distortion
like this kinda thing
Using Freeze Spray to Diagnose Faulty Electronics | Techspray
-
Unfortunately, the photo is blurry and the "X Marks the Spot" graphic obscures the item in question. Looking at the holes in the circuit board, it seems like there might be a ceramic disc capacitor that is somehow bent over the resistor underneath it (R 51). However, it looks blue compared to the other capacitors which all seem to be orange ceramic disc type. The components in that area look like D1 (presumably a diode), the mystery item, R51 which is a resistor and then D3 which is another diode, I think.
if it is a capacitor, you may be in luck as most of them have a code printed on them that tells you what the value is. Resistors have a colored band system for getting that information, which is a little bit of a nuisance if you're not used to it.
if you can provide a more in focus photograph and don't put a drawing on top of it, that would help us.
-
Yup, it's R51 all right. Schematic attached. I put a red dot next to 1/2watt resistor.
-
For reference next time someone is in need:
Mobile Schematic Heaven. Where All Good Amp & Effect Designs Await Resurrection...
-
OK, we have two threads covering the same information which is getting confusing. The updated photograph is in the "what's wrong with my amp" thread. It's still a little difficult to tell what we are looking at there. Is that a blue disk ceramic or tantalum capacitor that's partially disintegrated and bent over the R51 resistor? Or is the R51 resistor that badly blown out? I have never actually seen anything like either of those.
The schematic cited by GNAPPI indicates a 56K 1/2 watt resistor at R51, which is a standard part and easy to find. However, if it's actually a capacitor next to R51 (there appear to be holes in the circuitboard next to R51 and legs coming out of those to the mangled item), then that value is still uncertain because we don't know what circuit board reference number there is for that. If the OP can look closely at the circuit board under it, there may be a reference number under that fried component that can be referred to the schematic. If you look at the board, there are different shapes drawn on it for the different components (sort of a dogbone shape for resistors, oval or circle shapes for capacitors, etc.).
-
The component next to the resistor is likely C35, but unless the gunk is removed to see the silkscreen it's hard to tell.
-
Hmm, C35 looks like it's an electrolytic cap in the schematic, athough I'm a little puzzled by the numbers (100/33 = 100V, .33 cap? And does one leg of that cap go to ground?). Maybe it's C37, perhaps? Although the component progression in the photos looks like it ought to be C35.
Although does the schematic match that amp for certain? I don't see a D2 anywhere in the vicinity of R51 in the photo, unless it's mounted under the board, and it looks like it ought to be right there according to the schematic. The schematic references AP122 while the circuit board references AP0134-060B.
-
The only way to tell for sure where / what a component is to ring out its' pins on the PCB and see where the lands go I'm afraid.
-
R51 looks fine, it's the resistor underneath the blown component. Unfortunately, the photo is so blurry it's not possible for me to see what is actually blown. Moving it, so that the PCB underneath is legible, in a focused photo, would help. My first thought is that it's D2, but it doesn't look like the other diodes near it, D1 and D3. A better photo is needed.
-
I've got the same amp on the bench here now. I'll get some photos tomorrow. It's an unmarked component thats been attached to the body of R51 from the factory. Doesn't appear on the schematic. How weird!
-
There we go. Weird little disc thing, Its leads are connected across R51. Probably some sort of capacitor, I guess?
-
The burnt disc appears to be C37 which is just a small value ceramic disk cap. It looks like 240(?) pf from the schematic.
The schematic also shows "D22A" connected in parallel with R51. See the dashed arrow leading from "D2" (in parallel with R51) pointing to the hand drawn component in the upper left. Silk screen on the board shows D1 and D3 but no D2. So D2 must have been another diode soldered across the body of R51, as the hand drawn component suggests. Heat from R51 probably 'did it in'.
1S2473 diodes may still be available but could be hard to find. It could be replaced with a commonly available 1N4148 or 1N4448.
-
Originally Posted by va3ux
-
Originally Posted by xavosh
FWIW.
-
Originally Posted by rpjazzguitar
-
Originally Posted by xavosh
Also, the hand drawn 'D22A' shows R51 as 68 ohms, vs the 56 ohms on the main print. And the color code on R51 shows 68 ohms too.
-
Originally Posted by va3ux
-
Originally Posted by blue-moves
-
Originally Posted by benhatchins
As for further work, you can look for the tutorials on YouTube if you didn't find the solution here.
Enable GingerCannot connect to Ginger Check your internet connection
or reload the browserDisable in this text fieldRephraseRephrase current sentenceEdit in Ginger×Last edited by Eugle; 07-21-2023 at 03:43 AM.
2 new & excellent Jazz Comping Truefire...
Today, 10:22 PM in Comping, Chords & Chord Progressions