Diagnosis: GameBoy Advance SP - No Audio

Hi Christopher,

The speaker can be checked with a multimeter set to ohms, just to confirm it is ok (should be 100 ohm or lower resistance across the terminals of it) and just confirm it's still soldered or pressed fine onto the board (using the multimeter set to ohms and check the connections on the track if possible, or visually inspect that the speaker is still making good contact with the board).

Is there a volume control/slider/switch or anything? If so, those can sometimes fail. There a post here which talks about four solder connections on switches could be the issue:

https://gbatemp.net/threads/gba-sp-sound-not-working.468232/

For a sound issue, a crystal earpiece is really handy, you can move it around various points on the board, with no risk of damaging anything because the earpiece has a very high resistance so it doesn't load the circuit.

However, you might not need that, if the issue is solved by the other suggestions above. A 'scope can be used for that too but again I don't think it will be necessary initially.

Finally found batteries for my multimeter...

7.6ohms across the speaker, appears to make good contact with the PCB (it's stuck to the board with weak glue and prongs make contact). No sound still.

There's a volume slider, it has 6 solder points and those are very secure to the PCB.

I don't have a crystal earpiece or another way of testing the speaker at the moment.

Oh, hoped it would have been an easy thing with some failed contacts : (

The analogue channel on the bitscope could be used, by powering up the unit with a game installed and if it is known that sound should be playing for the game.

The contacts near the volume slider would need to be probed (with the bitscope ground connection connected to the battery negative contact), and the 'scope set to approx. 1 msec/division or thereabouts, and 0.5 or 1 V/div. Also, probing near any small chip or capacitors that may be part of the audio amplifier circuitry, it could be physically between the speaker and the volume control area, just to spot if the audio signal is detected. There appear to be lots of 3-pin SOT-23 sized parts and some capacitors in that area from the photo, so that might be the amplifier. Probing on the capacitors would be worth trying, and if audio does get spotted in that area, then maybe reheating some of the parts there could fix it (in case a solder joint has lifted due to button-presses flexing the board maybe.

Whats going on here? looks odd..

https://www.youtube.com/watch?v=iG-8Y6XKZzY

this guy had the same issue.. found that the speaker when pushed against the contacts worked.. around the 6 minute mark

I'll have a closer look at that..

Unfortunately the speaker is making good contact with the PCB.

Hi Christopher,

It looks like U3 (near the directional pad) is the audio chip, but it's custom so no datasheet. However connections near it could be probed to spot the audio signal, but also worth checking supply rails (there may be a separate analogue and digital supply rail), perhaps identifiable by screenprinting on the board of test points or signal names, or if there is a ground plane. In any case, it appears to be the same chip as on the Gameboy Advance (non-SP), so the schematic will likely be very similar. This is the GBA schematic for that area, and the supply rails can be checked plus the audio at LIN, RIN and the SPKOUT pins. There's also pin 12 which is labelled STB with a bar on top, so that could be inverted standby, and would need to be high for the chip to be enabled.

The part that Matt identified as looking odd could be water damage, and might be power related (supply regulation or switching a power rail on or off) so could well be the cause too. It might need some some examination or solder re-melting there, if any corrosion has damaged a join or track. I couldn't find what part it was, I think it says WBM on the SOT23-6 shaped part U7, but my attempts to google for it found nothing : (