One thing I never get tired of is making videos about modems. And above is a modem video! An Avtek Flash Modem 288 V.34 purchased second-hand in August 2022 with a serial number of 601000266. The model number is CD1500M, with the M at the end signifying that it is the Mac version. Being a Mac version the only difference appears to be the inclusion of a Mac-compatible serial cable.
To check the internals, I had to open the case and it might be an understatement to say that I had a little bit of trouble. The plastic was far more brittle than I would have liked aaaand all the clips holding it together snapped when attempting to open it.
And once the clips had snapped, I was able to look at the horrors inside. Those poor capacitors are not having a good time. Bad circuit design? Did someone not derate them? Orrrrr did we use a junk brand… Oh, Nichicon – is that you? A good example of why I don’t use Nichicon in anything.
Here’s an surface mount capacitor I’m pretty sure I didn’t replace because it was on the underside of the modem. There was no silkscreen with component numbering which was a little annoying.
At least the power supply was well built (solid). It’s a NetComm 9V AC 1A (240V AC 50Hz) with markings WW069 and N14311.
The Rockwell chipset is noteably absent and we have a Motorola chipset. The only other modem I’ve seen with a Motorola chipset to date is the Acer AcerModem 56 Surf (AME-MU00). Which is strange as NetComm/Sirius was well aligned with Rockwell and odd for Motorola, from what I understand from here most of their modems were internal.
But I guess this is just a rebadged Motorola made to look like an Avtek. Cost cutting perhaps or an attempt to diversity maybe. This Avtek doesn’t feel like an Avtek with it being reported as a Motorola Lifestyle 28.8 External in ROM.
I will admit that because I didn’t really need this modem – or want it. Due to the clips failing and it being beige, we might not have done the best job on the capacitor replacement. Using on-hand caps with pads lifting here and there. There are more photos in the photo gallery (surprise!) if you have a hunger for modem photos.
Below are the initialisation strings used, whether they are the best ones… I couldn’t be sure. But I’ll throw in some ATI (inquiry, information, or interrogation) results.
---------- 2022-09-02 10:25:09 +1000: Logging Started ---------- ATZ OK AT&D2X3V1Q0S7=70 OK ATI0 28800 OK ATI1 6318 OK ATI2 OK ATI3 Motorola Lifestyle 28.8 External 68356 ROM SW REV 6 S209415900 -01 03/13/97 10:00 AM OK ATI4 OK ATI5 LAST DISCONNECT: NO DIALTONE OK ATI6 ERROR ATI7 ERROR ATI8 ERROR ATI9 ERROR ATI10 ERROR ATDT1234567890 CONNECT 115200
Whoops looks like I didn’t quite have those init strings right and ended up with a DTE (modem to computer) instead of DCE (modem to modem) for that last command. Oh well, at least externally it looks OK, as long as you don’t try to pick it up.
Next is a listing of the capacitors replaced with order numbers are Element 14 (Australia). The capacitors were replaced in this modem in September 2022. The formatting isn’t too web friendly, copy the raw text out and paste it into a non-rich text editor (Such as Notepad or TextEdit – in plain text mode) and you’ll probably be fine. 😄
Value Voltage Width Height Notes 2200uF 16V 15mm 15mm 1144631 - Spacing 7.5mm, too tall needs to bend 120uF 16V 6mm 12mm 2346210 - Upgraded to 35V, wider 8mm 120uF 16V 6mm 12mm 2346210 - Upgraded to 35V, wider 8mm 120uF 16V 6mm 12mm 2346210 - Upgraded to 35V, wider 8mm 120uF 16V 6mm 12mm 2346210 - Upgraded to 35V, wider 8mm 220uF 16V 10mm 10mm 1144621 - SMD, replaced with radial (25V) 220uF 16V 10mm 10mm 1144621 - SMD, replaced with radial (25V) 10uF 100V 6mm 12mm 1144640 10uF 100V 6mm 12mm 1144640 10uF 16V 4mm 4mm 1144632 - SMD, replaced with radial 10uF 16V 4mm 4mm 1144632 - SMD, replaced with radial 10uF 16V 4mm 4mm 1144632 - SMD, replaced with radial 10uF 16V 4mm 4mm 1144632 - SMD, replaced with radial 47uF 16V 6mm 6mm 1144619 - SMD, replaced with radial 47uF 16V 6mm 6mm 1144619 - SMD, replaced with radial
Special thanks to: Doge Microsystems as always for their VoIP guides and Gough’s write ups on modem sounds.
As a footnote to a footnote, I’ve left Twitter because I do not agree with a lot of things the company- if you wanna call it a band, because it’s a one man name – has been doing as of late and Mastodon is getting a bit more traction as a Twitter replacement. Good riddance I say! 😎
This modem has been donated to the Australian Computer Museum Society (ACMS).
since sometime in the mid-1990s. We are powered by a 