A Boss HM-2 Problem!

[profsquid]

Hey guys,

Sorry to post this so early after joining, but I am at my wit's end!

I recently received a Boss HM-2(D1/R2 Jumpered) , which I would love to use, but it the LED will only light when a battery is connected. If I try to connect a 9V power supply, no joy. Anything obvious that I am missing? I know daisy chaining is an option, but I was wondered if there is any alternative before doing that?

Squid.

[Quackzed]

d.c. jacks go bad, id replace it, check its connections etc first. make sure its not a broken wire. also modded  mine to jumper the in line 'crossover' diodes. its now a good gritty highish gain distortion. gain goes from medium to high gain between 1and2 tho, so its not easy to dial in lower gain sounds but its called the 'heavy metal pedal' for a reason. 

[Mark Hammer]

1) Barrel plugs come in different shaft lengths, it can sometimes be the case that the plug you insert doesn't go in far enough to the jack to disable the battery and switch over to external DC.

2) It can also happen that 2.5mm plugs look an awful lot like 2.1mm plugs.  They will successfully insert into the jack, but they won't make proper contact.

3) It may also be the case that the wire leading up to the plug is fractured inside the shielding from too much bending.  It happens.  You can start by measuring the DC voltage at the output of the adaptor, and verifying that it is reading 9VDC or something close to it (when not plugged into anything, the voltage reading can often be higher than 9v; dropping down to around 9v when actually powering something).

[profsquid]

Cheers all, much appreciated. Any specific recommendations on power supplies to try with an HM-2 with previous mentioned mod? I know it might sound a bit dense, but checking just in case.

[charmonder]

before you mod it: note the ACA power supply! 

http://stinkfoot.se/archives/726

If it says "PSA" on the bottom (or on the sticker next to the adapter jack), use a 9 volt regulated supply.
If it says "ACA" on the bottom or on the sticker, it will need 12 volts on the adapter jack, rather than 9. Unless you are using a daisy chain or power supply with common ground for all outputs (DC Brick, Cioks, PowerPad etc). In that case, the pedal will work with 9 volts, as long as there's a 'proper' 9 volt pedal in the chain with it. And provided that there are signal cables connecting the pedals as well.

I was actually having this same problem, (that is my HM-2 pictured above) I can verify that it does indeed work on a daisy chain with PSA style boss pedals.

[charmonder]

The other thing I usually have to do with old pedals is scratch off the rust/dirt from the contacts of the AC jack. There's got to be a more proper way of doing this but I can usually get the job done with the end of a used guitar string.