Is a WROOM-02 WiFi module subtly different to an ESP-01S module

I have been prototyping on an ESP-01S module for some time using the Arduino IDE and this programmer.

I thought I'd change to a module with FCC approval so bought some WROOM-02 modules from RS Components. I made up a board to convert the pins from the ESP-01 pinout to an adapter for the WROOM-02 (and yes I've checked all the wiring a million times :slight_smile: but when I try to program it all I get is

warning: espcomm_sync failed

error: espcomm_open failed

error: espcomm_upload_mem failed

SPIFFS Upload failed!

Is there some subtle difference to the WROOM-02 I've missed. I bought three of them and they all have the same problem, and plugging the ESP-01S back in programs perfectly so I haven't broken the programmer.

Any suggestions gratefully received.

Do you have a pull-down resistor on gpio15?