Lexicon 480L HSP Card Repair PROMs

If you repair Lexicon 480Ls or are an informed owner then you will know that the custom-programmed bipolar PROMs are:

a) Statistically quite often the cause of faults.
b) Increasingly difficult to find replacements for.

We have certainly found that to be the case, particularly the large PROMs on the HSP cards. The failure mode is unknown; it may be an age thing, since cards have been encountered where more than one PROM has failed at the same time.

Each HSP card uses two 350-04721 CONTROL PROMs and two 350-04722 COEFF PROMs and most 480Ls have two HSP cards.

We are fortunate enough to have a small number of NOS original Lexicon spare PROMs in stock. They have all been verified against a known-good device but are otherwise unused. This limited opportunity to acquire spares is being offered to raise funds to acquire further Lexicon parts!

Please select the part you require from the drop-down list.

(Note: there are various other PROMs elsewhere in the 480L, but in our experience they are less problematic. If you have a requirement for any of these then we can probably help - drop us a line and we will add them to the list).

Thanks for looking - please feel free to email with any questions and see our other auctions for other vintage parts.