URGENT: Liability of sleeping partner

I am partner of a Partnership firm, comprising of Seven partners. Two of the partners, are running the business and they are working partners taking care of the day to day affairs of the firm. Other five partners, including my self is not in station and is sleeping partners. The cheques can be signed and issued by the working partners. In case, a cheque bounces and legal action takes place under section 138, are all the seven directors liable for legal action, or only those who have signed the cheque ?